Circulating pump for hot water heating system

ABSTRACT

A combined circulating pump and mixing valve for a hot water heating system comprises a single housing for the pump and the mixing valve. The mixing valve body is mounted in the housing between the hot and cold water inlets and the outlet, and the pump impeller is also mounted in the housing. The pressure differential produced by the impeller between its inlet and outlet is received by a device mounted in the housing, and this device controls the mixing valve body in response to the pressure differential transmitted to the device by the pump.

United States Patent Inventor Jost Eduard von Fellenberg [56] ReferencesCited h swillel'land UNITED STATES PATENTS Q 1 1969 1,819,045 8/1931Snediker 236/12A lf l f 1 1,990,653 2/1935 Kollsman.... 236/12A Assi neeHansA Troesch 2,542,273 2/1951 Brown 236/l2A g 2,550,907 5/1951 Brown236/12A Zurich, Switzerland Priority p 3 1968 2,985,107 5/1961 Anderson415/47 Switzerland 3,482,777 12/1969 Quinn 236/12A 13,213 PrimaryExaminerC. J. Husar Attorney-Kurt Kelman ABSTRACT: A combinedcirculating pump and mixing valve CIRCULATING PUMP FOR HOT WATER for ahot water heating system compnses a single housing for the pump and them1xmg valve. The m1x1ng valve body 1s HEATING SYSTEM h h d M l 9 Claims3 Drawing Figs mounted 1n the housing between t e 0t an co water n etsand the outlet, and the pump lmpeller 15 also mounted in the U.S.Cl415/47, housing. The pressure differential produced by the impeller236/12 between its inlet and outlet is received by a device mounted inInt. Cl F0lb /00 the housing, and this device controls the mixing valvebody in Field of Search 415/47; response to the pressure differentialtransmitted to the device 137/114; 236/12, 12(A) by the pump.

I 53 51 36 1.21 l 49 28 ,1 I g9 15 L7 34 T 66 32 30 20 71 21. 73 ll q 9u PAIENTYED JUN 1 Ian SHEET 2 BF 2 INVENTOR. JOST EDUMD V 'FELLWBE G ENTCIRCULATING PUMP FOR HOT WATER HEATING SYSTEM The present inventionrelates to a combined circulating pump and mixing valve wherein themixing valve body is controlled by means of the pressure differentialproduced between the inlet and outlet of the pump.

Conventional devices of this type are complicated in construction and,therefore, correspondingly costly and susceptible to breakdowns. In somefields of applications, particularly in heating systems, theynecessitate complex circuits and relatively involved installation.

The above and other disadvantages are overcome in accordance with thisinvention with a combined circulating pump and mixing valve for a hotwater system, which comprises a single housing for the pump and themixing valve. A hot water inlet and a cold water inlet open into thehousing, and a mixed water outlet leads from the housing. A mixing valvebody is mounted in the housing between the inlets and the outlet. A pumpimpeller mounted in the housing produces a pressure differential betweenan inlet and an outlet thereof, and a device receiving the pressuredifferential and responsive thereto is mounted, in the housing forcontrolling the mixing valve body in response to the pressuredifferential transmitted to the device by the pump.

The above and other features of the invention will become more apparentin the following detailed description of a now preferred embodiment,taken in conjunction with the accompanying drawing wherein FIG. 1 showsa pressure-difference-controlled valve arrangement in section along linel-l of FIG. 2;

FIG. 2 shows the valve arrangement in section along II-II of FIG. 1; and

FIG. 3 shows part of the spring-prestressing device.

The pressure-difference-controlled valve of the present invention issuitable for fitting into heating systems, for instance, and is designedas a mixing valve with a valve housing 1. This housing 1 is providedwith a hot-water inlet 3, a cold-water inlet 5 and a mixed-water outlet7. The valve arrangement is designed as a double-acting, single-bodyvalve having a valve seat 9 in the hot-water inlet and a valve seat 11in the coldwater inlet. The two inlets open into a mixing chamber 13,from which the mixed water passes through a centrifugal pump in alater-described manner into the outlet or pressure line 7. The valvehousing 1 carries a top housing 15 whose open top is closed with cover17, for instance by screw fasteners (not shown). A knob 18 is mounted incover 17, permitting manual operation of the valve. The valve housing 1comprises a valve-bearing support 20 for receiving a valve guide bush 26in which a valve spindle 24 is slidably mounted. One end of the-spindlecarries a valve body 22, while the other end has the shape of a rivetshank. The valve guide bush 26 threadedly is secured in the valvebearing support 20 although it may be press fit in the support, forinstance. An upwardly protruding part of the bush 26 has an externalthread 28 which carries a threaded ring 34 so connected to a pinion 30that the two rotate together. The pinion 30 is provided on its peripherywith a coarse toothing 32 by which it can be rotated. A coil spring 36rests with one of its ends against the pinion 30. Fitted to the upperend of the valve spindle 24 is a diaphragm 38 whose outer edge isfixedly held between the top housing 15 and the cover 17. A ring gasket40 seals off the chambers 68 and 69 'from outside. The center portion ofthe diaphragm 38 is gripped and held under tension by twodiaphragm-holding discs 42 and 43 in the manner shown in FIG. 1, andthis sandwich-type valve component is secured with the aid of a rivethead 45 to the free end of the valve spindle 24. The upper end of thespring 36 rests against the diaphragm-holding disc 42. The top housing15 has a bore in its sidewall, into which is fitted a guide bush 49. Apivotal lever'51, which has a handle and which can be moved in and out,is journaled in bush 49. A gasket 53 ensures the sealing towardsoutside.

A spyhole 55 with a glass 57 in a threaded holder 58 permits theoperator to look into the mixing chamber 13 and check the position ofthe valve body 22.

Adjoining the rear of the valve-housing portion defining the mixingchamber 13 is a pump housing portion 60 serving to receive an impeller61 of a circulating pump 62. The pump is shown in outline by brokenlines in FIG. 2. It is a centrifugal pump with an intake side 63 and adelivery side 64. In the illustrated embodiment, the pressure differencerequired to operate the system by producing the circulating action isdeveloped by the pump between the inlet and the outlet, or between themixing chamber 13 and the pressure or outlet line 7.

As mentioned, the diaphragm 38'divides the space confined by the tophousing 15 and the cover 17 into two chambers 68 and 69. The upperchamber 68 communicates through apressure bore 67 with the pressure side64 of the pump, while a second bore 66 leads from the intake side orlow-pressure side in the mixing chamber 13 to the chamber 69 below thediaphragm 38. For a better understanding, the drawing shows arrows 71for the hot water, 72 for the cold water, and 73 for the mixed water.

The idea underlying this valve arrangement with differential pressurecontrol is to employ the flow medium as the control medium and thusdispense with a special control circuit. The

arrangement uses the pressure difference of the flow medium or mediathrough the valve to adjust the control valve, as described later.

The hot water flows through the inlet 3 into the valve housing 1 and, ifthe valve body 22 is not closing the valve seat 9,

passes the valve body 22 and into the mixing chamber 13, where it mixeswith the cold water flowing through the inlet 5 and past the valve seat11 and the nonclosing valve body 22.

' Thence the mixed water is drawn by the circulating pump 62 and theimpeller 61 into the intake side 63 of the pump, whence, flowing throughthe impeller 61 with a corresponding increase in pressure, it passes tothe delivery side 64. The mixed water then leaves the valve housing 1through the outlet 7 In this process, different pressures prevail in thetwo chamresults in a correlated mixed-water temperature. Conversely,'

with the temperatures of hot and cold water given, the system involves adeterminate position of the valve body 22 with respect to the valveseats 9 and 11 and, accordingly, an appropriate equilibrium of theforces acting on the diaphragm 38. For the purpose of setting theconditions required, the system includes a power element, viz the spring36, which is adjustably pretensioned. This pretension can be varied bypivoting the lever 51, which engages the toothing 32 of pinion 30 andthus rotates the pinion 30 and so lifts or lowers it by means of thethreaded ring 34 mounted on the external thread 28 of the valve guidebush 26. By pulling out and pushing in, an indicated by arrows, it ispossible to set the lever 51 in the next gap between two teeth of thetoothing 32. Of course, the adjustment can also be effected by othermeans, such as a pinion with sunwheel toothing and a correspondingpinion rotatable from outside or by means of bevel gears.

With the force relations given, the setting of the valve arrangement fora particular speed of the circulating pump 62 is therefore determinate.Thus, if the flow through such a valve arrangement or the mixing ratiobetween hot water and cold water is to be varied, it will be necessaryto adjust the valve body 22 with respect to the two valve seats 9 and11. In the embodiment described, the simplest way of effecting such anadjustment is by varying the speed of the impeller 61 of the circulatingpump 62. This speed may be impulse-controlled from outside, as, in acentral heating system, by an outside thermostat and a forward-linewater thermostat acting on a regulator which varies the speed of thecircuiating pump 62 accordingly.

Thus, if the demand for heat rises, it will be necessary to increase theflow of heated fluid through the outlet 7. This can be effected by meansof a higher mixing temperature of the water and/or a higher mixed waterquantity. Thus, when the temperature falls below a preset level, thethermostats mentioned (not shown) will cause the regulator to givesignal to increase the speed of the motor of the circulating pump 62and. according to the pump characteristics, the quantity of mixed waterdelivered. And, according to the resistance parabola of the system, thedifferential pressure (circulating pressure) developed by the pump willalso rise, so that the increased difference between the forces acting onthe diaphragm 38 will move the valve body 22 towards opening for the hotwater, and towards closing for the cold water. This increases the hotwater input and reduces the cold water input. The mixed watertemperature rises, so that more and hotter water will flow from theoutlet then before the start of the regulating process. According to thecharacteristics of the diaphragm 38 and the spring 36 and also accordingto the static and dynamic liquid forces acting on the valve body 22, theoperation results in a new state of equilibrium, which can again bechanged in the manner described by varying the speed of the circulatingpump 62. It is therefore possible in a very simple manner to install thedescribed valve arrangement in a system and operate it without requiringa special regulating circuit with special regulating media.

Such a valve arrangement can also easily be fitted into an existingsystem, such as a central heating system, and tuned to the totalresistance thereof without requiring any further components. Suchadjustment or tuning is effected as follows:

At the maximum speed of the circulating pump 62, the pretension of thespring 36 is set by means of the pinion in such a way that the valvebody 22 comes to rest against the valve seat II of the cold water inlet5. Then the cold water supply is completely cut off. The maximum valuesof quantity and temperature are reached as the hot water supply is fullyopen and the delivery rate, determined by the top speed of thecirculatingpump 62, at its highest. This position can be easily observedthrough the spyglass 57. The adjustment is therefore extremely easy. Forthe rest, it is necessary to select spring 36 with the requiredcharacteristics so that, at the iowest speed of the circulating pump 62,the appropriate position of the valve body 22 is reached with respect tothe two valve seats 9 and 11. This may be other extreme position of thevalve, for instance, in which valve body 22 rests against the valve seat9 of the hot water inlet, so that only cold water is admitted andcirculated.

Such valve arrangements in heating systems, particularly in centralheating systems, are not only attractively simple in terms of regulatingtechnology, but also present great advantages as to trouble incidence,replacement, tuning to the existing system, and dependability.

I claim:

1. A combined circulating pump and mixing valve for a hot water heatingsystem, comprising a single housing for the pump and the mixing valve, ahot water inlet and a cold water iniet opening into said housing, amixed water outlet leading from said housing, a mixing valve bodymounted in the housing between the inlets and the outlet, a pumpimpeiler mounted in the housing and producing a pressure differentialbetween an inlet and an outlet thereof, and a device receiving thepressure differential mounted in the housing, said device controllingthe mixing valve body in response to the pressure differentialtransmitted to the device by the pump.

2. The combined circulating pump and mixing valve of claim 1, whereinthe pressure differential receiving device communicates with a chamberlocated in the housing upstream of the impeller inlet and with a chamberlocated downstream of the impeller outlet.

3. The combined circulating pump and mixing valve of claim 1, whereinthe pressure differential receiving device comprises a spring-load diahragm.

4. The combined circu ating pump and mixing valve of claim 3, whereinthe mixing valve has a valve spindle operating the valve body, and thediaphragm is directly connected to the valve spindle.

5. The combined circulating pump and mixing valve of claim 4, comprisingmeans for adjusting the spring load on the diaphragm for adjusting theposition of the valve body.

6. The combined circulating pump and mixing valve of claim 5, whereinsaid adjusting means comprises a displaceahie element attached to oneend of the spring.

7. The combined circulating pump and mixing valve of claim 6, whereinsaid element is a pinion movable from the outside of the housing.

8. The combined circulating pump and mixing valve of claim 1, whereinthe pressure differential device is arranged to close the hot waterinlet when there is no pressure differential.

9. The combined circulating pump and mixing valve of claim 1, furthercomprising a spyhole in the housing for observing the position of thevalve body.

1. A combined circulating pump and mixing valve for a hot water heatingsystem, comprising a single housing for the pump and the mixing valve, ahot water inlet and a cold water inlet opening into said housing, amixed water outlet leading from said housing, a mixing valve bodymounted in the housing between the inlets and the outlet, a pumpimpeller mounted in the housing and producing a pressure differentialbetween an inlet and an outlet thereof, and a device receiving thepressure differential mounted in the housing, said device controllingthe mixing valve body in response to the pressure differentialtransmitted to the device by the pump.
 2. The combined circulating pumpand mixing valve of claim 1, wherein the pressure differential receivingdevice communicates with a chamber located in the housing upstream ofthe impeller inlet and with a chamber located downstream of the impelleroutlet.
 3. The combined circulating pump and mixing valve of claim 1,wherein the pressure differential receiving device comprises aspring-load diaphragm.
 4. The combined circulating pump and mixing valveof claim 3, wherein the mixing valve has a valve spindle operating thevalve body, and the diaphragm is directly connected to the valvespindle.
 5. The combined circulating pump and mixing valve of claim 4,comprising means for adjusting the spring load on the diaphragm foradjusting the position of the valve body.
 6. The combined circulatingpump and mixing valve of claim 5, wherein said adjusting means comprisesa displaceable element attached to one end of the spring.
 7. Thecombined circulating pump and mixing valve of claim 6, wherein saidelement is a pinion movable from the outside of the housing.
 8. Thecombined circulating pump and mixing valve of claim 1, wherein thepressure differential device is arranged to close the hot water inletwhen there is no pressure differential.
 9. The combined circulating pumpand mixing valve of claim 1, further comprising a spyhole in the housingfor observing the position of the valve body.